Thursday was quite the day for Bristol-Myers Squibb’s Opdivo. After becoming the first med to succeed in a Phase III gastric cancer trial, the drug nabbed an FDA approval in head-and-neck cancer--and evened the score in that market with nemesis Keytruda in the process.

The regulatory nod–for use in patients whose disease has progressed on or after platinum-based chemo–comes based on Phase III study results that showed Opdivo could extend median overall survival. The checkpoint inhibitor prolonged patients’ lives by an average 7.5 months, compared with 5.1 months for those on any one of three standard-of-care treatments.

The approval opens up Opdivo–which already boasts approvals in melanoma, non-small-cell lung cancer and renal cancer–to a new patient pool. In 2016, forecasts expect 64,000 new cases of head-and-neck cancer, resulting in more than 13,000 deaths, Bristol said.

And while that population doesn’t measure up to the number of lung cancer patients, for instance, the approval is still a key step in BMS’ attempts to top the checkpoint inhibitor space. There, Opdivo is battling archrival Keytruda from Merck–which already has a head-and-neck cancer indication–as well as relative newcomer Tecentriq from Roche.

Now that the Bristol and Merck drugs are squared away in head-and-neck cancer, they’re fighting for market share in three different areas. Both drugs started off as melanoma treatments, and since then, they’ve both racked up lung cancer indications–though Keytruda recently took the lead in that arena after Opdivo flopped a first-line monotherapy trial.

Earlier Thursday, though, Opdivo picked up an edge in a so-far-untapped market. The med topped placebo at extending overall survival among chemo-intolerant gastric cancer patients or those who failed to respond to chemo.